Solve for $z$. $42=-7(z-3)$ $z =$
Solution: Let's divide and then add to get $z$ by itself. $\begin{aligned}42&=-7(z-3) \\ \\\\ \dfrac{42}{{-7}} &= \dfrac{-7(z-3)}{{-7}} ~~~~~~~\text{divide each side by } {-7}\\ \\ \dfrac{42}{{-7}} &= \dfrac{\cancel{7}(z-3)}{\cancel{{{-7}}}} \\ \\ \dfrac{42}{{-7}}&= z-3\end{aligned}$ $\begin{aligned} -6&= z-3 \\ \\ -6 {+3}&= z-3{+3}~~~~~~~{\text{add }3} \text{ to each side to get } z \text{ by itself }\\ \\ -6{+3}&= z-\cancel{3}{+\cancel{3}}\\ \\ -6{+3} &=z\end{aligned}$ The answer: $z={-3}~~~~~~~~$ [Let's check our work!]